Originally Posted by
Sport_Pilot
There is or was a relay for retracts that would work. But now it is built into the servo. I think the scale sites would have something like this.
If you ever need one for a project , the ones I use to control the lights on my night flyers are ;
"Dimension Engineering Pico Switch"
If you search that you will find that it's a cool little relay with both NO and NC contacts that is perfect for all kinds of RC switched power applications and can be had for the reasonable sum of $19.95
To source a relay , relay driver chip , and the few other SMT components (plus a tiny circuit board) I don't think I could build one for under $20 and these work fantastic .
Thing is , the OP would still need a TX/RX to activate the relay and of course the needed batteries and light in the training dummy , It's the TX/RX cost that I think will drive him away from using "hobby grade" gear rather than "toy grade" . Knowing the OP's working budget would help narrow the choices of available equipment ....